In an experiment published in the July 4 edition of Science, Stanford University postdoctoral fellow Jonathon H. Stillman examined the effect of climate change on porcelain crabs (genus Petrolisthes) inch-long invertebrates that inhabit coastal areas throughout the Pacific Ocean. Stillman discovered that porcelain crabs in the cool Pacific Northwest have the ability to adjust to larger increases in habitat temperature than crabs living in the warm coastal waters of Mexico.
The study showed that cold-water crabs have a greater capacity to adjust their heat-tolerance thresholds than warm-water crabs," said Stillman, who conducted the experiment at Stanford's Hopkins Marine Station in Pacific Grove, Calif. This is definitely counterintuitive. You would expect heat-tolerant organisms to be the most resilient to global warming, but it turns out they may have a harder time surviving as their habitat temperatures increase," he added, noting that a half-degree increase in the Earth's temperature could be enough to wipe out countless porcelain crabs:
Thermal tolerance
Stillman's experiment focused on four species of porcelain crab two from the chilly coast off Cape Arago, Ore., and two from Puerto Peasco, Mexico, located on the Gulf of California.
The Oregon species P. cinctipes and P. eriomerus reside in intertidal habitats where ocean temperatures range from 47-59 degrees F (8-15 C). The temperature of P. cinctipes, which lives higher on shore in the upper intertidal zone, can be as high as 88 F (31 C) during summer low tides.
The Mexican species P.
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Contact: Mark Shwartz
mshwartz@stanford.edu
831-239-3312
Stanford University
3-Jul-2003